In recent years, fluid handling devices have been used to accurately and speedily analyze a trace substance such as protein and nucleic acid. Fluid handling devices advantageously allow the amount of reagents or samples required for analysis to be small, and are expected to be used for various uses such as laboratory tests, food tests, and environment tests.
A fluid handling device is known which highly accurately detects a target material (such as a cell, a DNA and an enzyme) included in a micro droplet (hereinafter also referred to as “droplet”) which has a diameter of 0.1 to 1000 μm, both inclusive, and is generated from a liquid containing the target material. During generation of droplets, not only a droplet which contains the target material but also a droplet which does not contain the target material can be generated. In view of this, a liquid handling device is known which includes a sorter part for sorting the droplet which contains the target material and the droplet which does not contain the target material (see, for example, PTL 1).
FIG. 1 is a schematic view for describing a function of a sorter part of liquid handling device 10 disclosed in PTL 1. As illustrated in FIG. 1, liquid handling device 10 includes channel 11 through which liquid can move, and a pair of electrodes 12 for applying an electric field to the inside of channel 11. The pair of electrodes 12 is arranged along channel 11. In FIG. 1, white droplet 1 represents a droplet which contains a target material, and black droplet 1 represents a droplet which does not contain a target material. In liquid handling device 10, electrode 12 applies an electric field to the inside of channel 11. Droplet 1 having passed through the electric field in channel 11 moves in different directions depending on whether the target material is present. Liquid handling device 10 disclosed in PTL 1 can sort droplet 1 which contains a target material and droplet 1 which does not contain a target material by utilizing dielectric migration.